Algae and other microbial growth can be found in, and on structural members of buildings, including ceilings, floors, interior and exterior walls, and roofs, among other locations. Although algae growth does not typically threaten the structural integrity of building members, it can be unsightly. Removing algae and other microbes from buildings can be costly, and, if the problem is not resolved, can lower property values. Algae outbreaks can be seen in some building materials as dark stains and blotches; this can give the structure a deteriorated look, even though in most cases the algae is present predominantly on the surface of the material. The blue-green algae Gloeocapsa magma is a common microbe that can be found on roofs and exterior walls of buildings. Structural infestation by this algae is extensive in warm and humid climates, but is also commonplace in moderate-temperature, cooler areas. Infestations on roofs and walls are typically noticed first as dark spots, and then develop into long dark streaks as the algae reproduce and are carried by rain waters across the surface.